205007 12 Posted December 15, 2007 ok so ive tried the following things to reduce the idle speed on my 1600 gti (1991) wound idle screw all the way in until it stops checked for air leaks especially on inlet mani replaced TPS disconnected SAD retarded ignition all the way! and she still ticks over very high if i blip the throttle she returns to 1000 rpm for a second or two then straight back to 1500rpm i have set the tps switch up too but makes no difference ran out of ideas..... help! Share this post Link to post Share on other sites
Pugnut 9 1 Cars Posted December 16, 2007 what happens when you clamp the sad line ? is the tb butterfly closed when the throttle cable is slack? has anyone played with the the screw that adjusts the butterfly? and lastly , is there slack in the throttle cable on tickover ? Share this post Link to post Share on other sites
205007 12 Posted December 16, 2007 oh not sure about the butterfly screw where is that located? i have adjusted the cable so its just slightly slack which side of the sad do i clamp? the one from the inlet? rpm is not affected when i disconnect the tps or sad either Share this post Link to post Share on other sites
matty_gti 20 Posted December 16, 2007 Mate of mine had the same prob, turned out to be an air leak from a hose. Double check ALL of them and check them well. Ive got the same prob on my 1.6 but i just havent had time to have a look at it yet Matt Share this post Link to post Share on other sites
welshpug 1,626 Posted December 16, 2007 have you got a haynes workshop manual? detailed specifications on throttle body and idle setup are listed in great detail Share this post Link to post Share on other sites
saveloy 8 Posted December 16, 2007 If all of that doesn't do it, then it is most likely a duff spring within your air flow meter. Share this post Link to post Share on other sites
DamirGTI 327 Posted December 16, 2007 Hi ! I've had similar problem and it was the SAD - there was no 12v feed via connector to the SAD heater so it was stuck open all the time , the temp. of the engine coolant isn't enough to make it fully close especially if the coolant temp. drops down to 75deg. and if the connector doesn't provide 12v to the heater to fully close the SAD bimetallic strip it will open up again and start to increase the revs ... was very annoying ... Cheers ! Damir Share this post Link to post Share on other sites
Tom Fenton 1,526 Posted December 16, 2007 You can rule out the SAD easily enough by clamping off one of the hoses to it; if clamping off a hose drops the idle right down then either the SAD is not closing off, or there is an air leak somewhere. If clamping off a hose does not drop the idle speed down, then the SAD is closing and hence working properly. Share this post Link to post Share on other sites
steve@cornwall 100 Posted December 16, 2007 Has anyone played with the throttle stop screw? Share this post Link to post Share on other sites
205007 12 Posted December 16, 2007 i assume that is the butterfly screw? dont know where that is Share this post Link to post Share on other sites
steve@cornwall 100 Posted December 16, 2007 i assume that is the butterfly screw? dont know where that is On top of the throttle body there's a small screw which goes through a casting. The end of this can be adjusted to stop the throttle from fully closing. If yours will turn, it's been played with before, as they are tamperproof from the factory Share this post Link to post Share on other sites
simonb 0 Posted December 18, 2007 Try turning the the TPS all the way (hard) to the right (standing at the front of the car). The spindle inside the throttle body which the TPS is slotted into may have become stuck and needs freeing up in order to reduce the idle. Share this post Link to post Share on other sites
205007 12 Posted December 19, 2007 all sorted now, cam timing out and also changed thge whole throttle assembly jobs a good un! Share this post Link to post Share on other sites
